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Another seven people were injured in the accident

Eight people have died in a chemical accident in the basement of a Bangkok bank, officials have confirmed.

The contractors were working on a fire safety system at the headquarters of the Siam Commercial bank on Sunday night, the bank said in a statement.

They apparently suffocated after a gas mixture which depletes oxygen was released.

Another seven were injured in the incident, which may have been caused by contractors' "negligence", it added.

A bank spokesman told the BBC the incident took place in a vault storing documents in the head office in Bangkok.

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The bank said at around 21:30 local time on Sunday (14:30 GMT), an aerosol system called pyrogen was "inadvertently activated and exhausted all the oxygen in the area" as contractors were working on it.